In the outside markets, the NYMEX crude oil is $1.25 per barrel lower, the dollar is higher and the Dow Jones Industrials are 49 points lower.

Sue Mortensen, Advantage Ag vice-president, says the weather unknowns, not knowns worry the market. "We know it is hot, we know it will cool off on the weekend (but not be cool, rather be normal), what we don’t know is if it will rain. With corn tasseling, this is a key week. I am sure pix of corn fields will be forwarded like gangbusters," Mortensen says.

Beans lag simply because their development isn’t as crucial right now, she says.

"Plus, a popular trade earlier in the year was to be long beans and short corn. As corn pollination weather has gotten so much attention recently, the tendency is to buy corn and sell beans (getting out of the spread)," Mortensen says.

Mortensen adds, "Finally, we have weather forecasts every six hours to trade in this virtually continuous trading environment. Actually, the forecasts come every couple of hours, alternating between the GFS and the European. Volatility will continue as traders assess each model output."

Jack Scoville, PRICE Futures Group vice-president, agrees that it is definitely a weather market, and most of the Midwest looks hot and dry for at least the next week.

"Speculators started buying last night, and bought again in early trading. Now, it seems like we have turned sideways and slow. Maybe partly holiday, maybe partly waiting for the next model runs for the next forecast," Scoville says.

A tweet reported Monday that WeatherRisk.com is finding potential for a change in the weather for the second half of the month, he says.

"Corn tasseling in Ohio and Indiana is happening with stalks at 5 feet and under. Corn and beans had good color, but looked short in eastern Wisconsin over the weekend. Without a big change in the weather the price down side should be limited," Scoville says.